Fish Hoek Exclusion Net Evaluation Report

JULY 2014

Contact:

City of Cape Town Amy Davison [email protected] 021 487 2135

Shark Spotters Dr. Alison Kock [email protected] 072 661 9516 FISH HOEK EXCLUSION NET EVALUATION REPORT

1. Introduction

1.1. Background and history

It is well established that there is a high spatial overlap between water users and white sharks (Carcharodon carcharias) in the inshore areas of False Bay, South Africa (Engelbrecht 2013, Kock et al. 2013). Since 2004, Fish Hoek beach has experienced high white shark presence and has suffered three shark attacks, two of which were fatal. White shark presence and use of this bay is a natural phenomenon and is set to continue into the future. As a result, recreational and social use of Fish Hoek, as well as social perceptions of the beach, has been negatively impacted.

The City of Cape Town has adopted a non-lethal approach to shark attack mitigation (Nel & Peschak 2006). In addition to the Shark Spotters programme, the City investigated the possibility of additional non-lethal shark attack mitigation for Fish Hoek following a serious attack in 2012. A consultation process followed, in which the City of Cape Town Environmental Resource Management and Sports, Recreation and Amenities departments, and the Shark Spotters met with local councillors, representatives of the Fish Hoek Surf Lifesaving Club, representatives of the national Departments of Environmental Affairs (DEA) and Agriculture, Forestry and Fisheries (DAFF), and relevant local NGOs to draw up plans for the design and operation of an exclusion net. This process resulted in the design of an exclusion net that is deployed and retrieved daily, unlike traditional shark exclusion nets, which are permanently fixed in position. The overall goal of this process was to develop a solution with low environmental impact.

A research permit (RES 2012/94) was granted by DAFF and DEA in February 2013 for the trial operation of the exclusion net. The City of Cape Town, in conjunction with the Shark Spotters, was able to start trials towards the end of March 2013. In January 2014, the permit was extended until the end of May 2014 (RES 2014/02). These trials have been largely successful, and have been a critical learning experience for the City of Cape Town and the Shark Spotters.

1.2. Purpose

The purpose of this report is to provide a full assessment and evaluation of the trial of the Fish Hoek Exclusion net. As per the research permit, the City is required to assess the trial in terms of a number of criteria stipulated in the permit (Annexure A). Additionally, this report will provide an overall assessment of the success of the project, as well as recommendations for the future of the exclusion net.

2. Design and deployment

2.1. Net design principles

The design and layout of the exclusion net (attached as Annexure B) has been informed by a number of variables with the explicit intention of designing an exclusion net that addresses a range of informants. These variables include ecological considerations, coastal process deployment and retrieval logistics and structural considerations as well as recreational and economic considerations. Each of these principles is described below:

a) The net is located in the most sheltered part of the bay. The corner opposite the restaurant alongside Jagger’s Walk, has been determined to be the optimal area for deployment. b) Central to the design and layout is the need to reduce the ocean force, wave and wind action on the net. As such, a diagonal design where the net runs as close to parallel as possible to wind, wave and currents was formulated. c) The net is deployed and removed on a daily basis, and is not a permanent installation. This minimises the risk of entanglements of large fish, sharks or marine mammals, as the net is monitored throughout the day and is not left unattended. Additionally, the highest risk of entanglement is at night. d) Deployment of the net does not extend into the area predominantly used by the trek net fishermen. The City has consulted and will continue to consult with the trek net fishermen on an ongoing basis to ensure that any impact on their operations is minimised. e) The area enclosed by the net is large enough to allow for adequate recreation space as well as a training space for lifesaving requirements f) The mesh size of the net is small enough to minimise the risk that large fish and marine life, including sharks and marine mammals, are not entangled in the net, but large enough to ensure that the net does not entangle small fish species. Two small escape panels have been fitted to allow small fish to move in and out of the netted area. These panels have been monitored for fish movements. g) Adequate land based attachment and anchoring points have been installed. h) Water depth does not exceed 5m at any point so as to reduce the size and weight of the net i) The net is only deployed when conditions are suitable; during periods of bad weather – including strong south east winds that generate strong wave chop – the net is not deployed, or is removed if already deployed that day. j) No anti fouling substances have been used on the net, to reduce the possible ecological consequences. As the net is deployed on a daily basis, fouling is not a significant problem. Should fouling occur, the net will be air dried and exposed to sunlight.

2.2. Summary of net deployment and retrieval process

Early trials established that manoeuvring the exclusion net in its fully deployed configuration is not possible due to the drag of the weighted ropes on the sea floor. Therefore an alternative solution was proposed; the exclusion net is bunched up along its length into a “sausage” formation which is lashed in place by a number of small ropes with clip attachments.

In this formation the net is fed out from the trailer by the beach crew and pulled to the attachment point at Jagger’s Walk by a 4.5m rubber duck. Once attached at all three anchor points (beach, sea and catwalk) it is unfastened along its length by the boat crew to fall down like a curtain and form a complete barrier from sea floor to sea surface. The length of the net is then inspected by snorkel divers to ensure it is sitting correctly on the sea bed. A bright yellow flag is hoisted to indicate the Net area is enclosed and the net is in place.

The retrieval involves the boat crew ‘lifting up the curtain’ again along the length of the net by hand and fastening the bottom rope to the top (again in the ‘sausage’ configuration), and then disconnecting it from the catwalk and sea anchor point. Prior to this the yellow flag is lowered. The beach crew then pulls the net in towards the beach by hand, and packs it away onto the trailer. The net is stored on the trailer in a container near the Fish Hoek Surf Lifesaving Club.

2.3. Deployments and retrievals

The shark barrier was successfully deployed 130 times from 22 March 2013 – 3 May 2014, for an average duration of 7 h 40 min (SD = 28 min) per deployment. The deployment and retrieval times improved throughout the trial, from 145 min (SD = 67 min) for deployment and 84 min (SD = 23 min) for retrieval in April 2013, to 46 min (SD = 12 min) and 57 min (SD = 13 min) respectively, in April 2014. During the first half of the trial (March – September 2013) the exclusion net was deployed on an ad hoc basis, and starting from October 2013 it was deployed more consistently over weekends, public holidays and school holidays (Table 1).

Table 1. Number of exclusion net deployments per month (deployment times, retrieval times and duration in the water) from 22 March 2013 – 3 May 2014. Month No. Deployment time Retrieval Duration in the water time Min Max Avg Min Max Avg Min Max Avg Total Mar 1 ------Apr 4 00:43 04:00 02:25 00:51 01:43 01:24 00:27 06:00 03:14 12:59:00 May 0 ------Jun 1 ------Jul 7 00:55 02:54 01:18 01:12 01:41 01:24 01:11 04:29 02:23 14:18:00 Aug 5 00:39 02:17 01:24 01:02 02:14 01:21 02:00 03:23 02:38 13:14:00 Sep 6 00:47 01:03 00:54 01:13 01:25 01:19 03:46 06:32 05:34 22:19:00 Oct 14 00:38 01:01 00:51 00:55 02:25 01:22 03:38 07:20 05:44 68:59:00 Nov 9 00:42 01:20 00:51 00:56 01:13 01:03 06:10 06:46 06:47 47:32:00 Dec 19 00:34 01:32 00:54 00:46 01:20 01:00 06:16 08:43 07:40 128:03:00 Jan 18 00:34 01:29 00:58 00:46 01:26 01:03 06:35 08:05 07:32 113:12:00 Feb 22 00:27 01:40 00:52 00:42 01:28 00:55 02:37 08:18 07:12 151:31:00 Mar 8 00:38 01:08 00:53 00:50 01:10 00:59 05:00 08:10 07:32 60:21:00 Apr 13 00:33 01:16 00:46 00:41 01:20 00:57 07:05 08:38 07:40 99:48:00 May 3 00:33 00:42 00:38 00:54 00:54 00:54 07:00 07:35 07:18 21:56:00 Total 130 754:12:00

2.4. Operational times

The operating team aimed to deploy the net whenever possible on weekends, public holidays and school holidays, and the entire months of January and February (weather permitting). Between December 2013 - May 2014 the net was deployed on 70.5% of potential deployment days, with unfavourable sea and weather conditions accounting for the times that it could not be deployed. The net was not generally deployed during the winter months (May - August) due to lack of demand, as well as adverse weather conditions. The official operating hours of the net (fully deployed) were 9am - 5pm. However, on occasion these times were affected by fishing activity or the presence of large marine animals (whales, dolphins or sharks) which delayed deployment, or incoming weather conditions, which resulted in early retrieval of the net.

2.5. Limiting conditions

Trialling of the net revealed that deployments and retrievals are hampered by large swell (>2 m) from the S, SSW and SE and strong SSE and SE winds (±30 km/h), with the combination of the two compounding the problem. The deployment of the net is therefore limited to fair - moderate weather conditions.

2.6. Final evaluation

The design of the net has proven to be suitable, has met the requirements laid down at the beginning of the trial, and has withstood the sometimes harsh sea conditions that it is exposed to. The following key points must be noted:

a) The mesh size (45mm x 45mm) is appropriate. No entanglements of either small or large fish occurred. Fish were observed behaving normally in the presence of the net. b) The material selected for the net is appropriate, and has generally withstood the sea conditions that it is exposed to. Some repairs to the net were required, however because of the ease of obtaining the rope that was used (a standard size and type), these repairs were simple and cost effective to make. c) The location of the net in the corner of the bay in front of the Galley Restaurant has meant that the net is well used due its location at the most popular part of the beach. The location of the net has not significantly impacted on the operations of the treknet fishers. d) The land and sea based attachment points have remained in place and withstood the strong forces placed on them by the net and ocean currents. e) No significant fouling of the net occurred. f) The system of deploying and removing the net daily has proven to be effective and significantly reduced the risk of entanglement or loss of the net, as the net is under constant surveillance. Over time, as the crew gained experience, the time taken to deploy and retrieve the net was reduced to acceptable levels. g) Deployments were possible on 70.5% of potential deployment days

3. Environmental monitoring

3.1. Methods

Together with the City, the Shark Spotting programme was responsible for the implementation, daily management and monitoring of the trial. During all operations the exclusion net was under constant surveillance by Shark Spotters to ensure that it remained in position and to initiate pro- active measures to deter cetaceans when necessary. A specially designed environmental monitoring programme was set up at the start of the trial to assess how various species, including sharks, fish, dolphins and whales reacted to the presence of the exclusion net, and to record any bycatch or entanglements.

Monitoring took place from 1 May 2013 – 3 May 2014, however the graphs presented below depict results for 1 May 2013 – 30 April 2014. Individual Shark Spotters were responsible for recording observations and assigned to six-hour long shifts (morning shifts from 7:00 – 13:00 and afternoon shifts from 13:00 – 19:00). Furthermore, Shark Spotters completed daily data sheets and recorded all deployment and retrieval information and animal presence and behaviour associated with the net. Animal behaviour was categorised by presence a) within the exclusion zone (within), b) 0-200 m from the exclusion net (near) and c) >200 m from the shark barrier (far). Complete tables of sightings are available as Annexure C.

All statistical analyses were done in STATA version 11.2

3.2. Effects on wildlife

3.2.1. Sharks and rays

White sharks The total number of shark sightings for Fish Hoek from 1 December 2004 (start of Shark Spotting programme) to 3 May 2014 stands at 431. During the exclusion net trial monitoring period, Shark Spotters recorded 39 white shark sightings on 22 different days. The first white shark sighting of the 2013/2014 season occurred on the 19 October 2013, but unlike previous years, where shark sightings peaked over October and November (Weltz et al. 2013); the number of sightings only peaked in January and February (Fig. 1). This peak coincided with a peak in the occurrence of bait fish such as mullet (Liza richardsonii) and game-fish such yellowtail (Seriola lalandi) as well as warmer waters (Fig. 1). As with previous findings (Kock et al. 2013), white shark sightings were only recorded from October to May (Fig. 1 & 2). The exclusion net deployments overlapped with the occurrence of white shark sightings (Fig. 2). These results provide strong support for continuing deployment of the exclusion net from October to May.

12 20 18 10 16 C) 14 ° 8 12 6 10 8 4 6 Water Water temprature ( 4

Frequency (no. days observed) days (no. Frequency 2 2 0 0 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Month

White sharks Game fish Bait fish Median water temp

Figure 1. Frequency (number of days observed per month) of white sharks (Carcharodon carcharias), bait fish e.g. mullet (Liza richardsonii) and game fish e.g. yellowtail (Seriola lalandi) and median monthly water temperature for Fish Hoek over the monitoring period (1 May 2013 – 30 April 2014).

5 Frequency (no. days obseved/deployed) days (no. Frequency

0 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Month

Exclusion net White sharks

Figure 2. Frequency (number of days observed per month) of white sharks (Carcharodon carcharias) and of exclusion net deployments (numbers of days deployed per month) in Fish Hoek over the monitoring period 1 May 2013 – 30 April 2014.

White sharks entered the bay 22 times (56%) when the exclusion net was not deployed and 17 times (44%) when the exclusion net was deployed. Shark behaviour was categorised by presence a) within the exclusion zone (within), b) 0-200 m from the shark barrier (near) and c) >200 m from the shark barrier (far) (Fig. 3). When the exclusion net was not deployed, white sharks entered the exclusion zone ten times (47.6%, n = 22). When the exclusion net was deployed, white sharks did not enter the exclusion zone. Furthermore, when they did enter the bay while the exclusion net was deployed, the sharks spent the majority (72.2%) of the time >200 m away from it. There was a single occasion (2 May 2014) when a medium-sized white shark (~3.5 m) swam directly towards the net (<5 m) and then abruptly turned away from it. Four records could not be included into either category due to incomplete information collected. Furthermore, due to the combination of small sample size and not being able to address the issue of the pseudo-replication i.e. individual sharks could not be identified; statistical tests could not be applied. However, the results still clearly demonstrate that the exclusion net is effective at keeping white sharks out of the exclusion area.

4 No. white shark sightings shark white No. 2

0 Within Near Far Exclusion net - not deployed 10 5 5 Exclusion net - deployed 0 2 13 Figure 3. Frequency (total number of sightings) of white sharks (within, near and far) in Fish Hoek when the exclusion net was a) not deployed and b) when it was deployed (n = 35).

Other sharks Bronze whalers (Carcharhinus obscurus) (n = 4) and smooth hammerhead sharks (Sphyrna zygaena) (n = 1) were also recorded while the net was deployed. As with the white sharks, none of these shark species penetrated the exclusion net. On two occasions these smaller sharks were recorded within 50 m from the net, and on a third occasion there were up to 10 of these sharks at one time, but they were >200 m from the net. The results demonstrate that other species of shark were also successfully excluded from the area covered by the exclusion net.

Rays Large black stingrays (most likely Dasyatis brevicaudata) were recorded 18 times (on 16 different days) while the net was deployed. Up to 13 stingrays were observed on a single day and recorded for many hours at a time. There were 4 records of the stingrays interacting with the exclusion net. On 1 occasion (8 October 2013) a single stingray got inside the exclusion net area before the net was fully unclipped. On 2 occasions stingrays was observed swimming right next to the net and on the fourth occasion a stingray was observed resting (stationary) right next to the net. The rest of the time the stingrays remained >50 m away. On 1 occasion a small guitar shark (Rhinobatus annulatus) was observed by a diver swimming underneath the exclusion net by burying underneath it. The results demonstrate that large rays were also successfully excluded from the exclusion area.

3.2.2. Fish

General There were 107 observations of fish schools present in Fish Hoek during the monitoring period (Fig. 4). The species most frequently recorded were mullet (Liza richardsonii), sardine (Sardinops sagax) and yellowtail (Seriola lalandi), but species identification could not be confirmed all of the time, especially for the baitfish species unless they were caught by the treknet fishermen; these were therefore recorded as ‘unknown’. Other species identified were kabeljou (Argyrosomus inodorus), white steenbras (Lithognathus lithognathus) and skipjack (Katsuwonus pelamis). Fish presence was seasonal, with a peak in observations in January and February. Overall, the net was deployed 58 times (54%) when fish were present in Fish Hoek.

12 20 18

10 16 C) 14 ° 8 12 6 10 8 4 6 4 Water temperature (

Frequency (no. days observed) days (no. Frequency 2 2 0 0 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Month

Game fish Bait fish Unknown sp. Median water temp

Figure 4. Frequency (number of days observed per month) of fish (bait fish, game fish, unknown species) and the median monthly water temperature for Fish Hoek over the monitoring period (1 May 2013 – 30 April 2014).

Baitfish (mullet, sardine, unknown) Baitfish were observed on 72 occasions over the monitoring period. When the exclusion net was not deployed, baitfish (sardines and mullet) rarely entered the exclusion area (6.9%, n = 5). Bait fish were observed 34 times (47%) when the exclusion net was deployed and came close enough to the net to interact with it on 9 occasions; the rest of the time they were too far away to interact directly. Out of these 9 observations all except one describe the bait fish as swimming towards the net, then swimming alongside it, before swimming away from it again. There was a single record (29 October 2013) of what the observer described as unusual behaviour where the baitfish swam towards the net and then immediately away from it. The results suggest that baitfish of various species were not adversely affected or scared away by the exclusion net, but that generally once they approached the net they swam alongside it.

Yellowtail Yellowtail were observed on 21 occasions over the monitoring period. There were no records of yellowtail present within the exclusion area when the net was not deployed, demonstrating that the fish rarely used the area enclosed by the exclusion net. There were 14 observations (66%) of yellowtail present in Fish Hoek while the exclusion net was deployed. There was a single record (7.1%) of a school of yellowtail 0-50 m from the net. In this case, the yellowtail swam towards the net, and as they got close to the net they changed direction quickly and swam away from it. The rest of the time, the yellowtail stayed >50 m away from the net and did not directly interact with it. It is possible that, as with the white sharks, the yellowtail stayed away from the net. However, given that there were no records of the fish coming that close to the area (even when the net was not deployed), it suggests instead that the area enclosed by the net is not used regularly and the net is therefore unlikely to have an adverse impact on the fish.

Skipjack, steenbras, kabeljou, Skipjack (n = 8), steenbras (n = 2) and kabeljou (n = 1) were observed on 11 occasions over the monitoring period. There is a single record of kabeljou entering the exclusion zone when the net was not deployed. On 8 occasions the exclusion net was deployed, and in all cases the fish stayed >100 m away from the net.

Note: According to the catch records from DAFF, the fish identified as Skipjack in the Shark Spotter data, could in fact be Kabeljou instead.

Sunfish Sunfish (Mola mola) were recorded in the bay on 5 occasions (4 times when exclusion net was deployed). On all occasions they stayed >100 m from exclusion net.

3.2.3. Marine mammals

Whales There were 69 records of whales in Fish Hoek during the monitoring period (Fig. 5). The majority of these records are most likely of Southern right whales (Eubalaena australis) although there was at least one record of a humpback whale (Megaptera novaeangliae) and one of a Brydes whale (Balaenoptera brydei). Over the monitoring period there were no observations of whales within the exclusion area when the net was not deployed, demonstrating that they rarely, if ever, use this area. Whales tended to stay in the deeper waters, >200 m away from the exclusion area. However, the location of the whale was not always recorded when the net was not deployed.

Whale presence peaked during August to October, with most sightings in September. The majority of exclusion net deployments took place outside this time, which meant the risk of entanglement was reduced. There was however, a high overlap of whale sightings and exclusion net deployments in October which highlights the need for the exclusion net team to be extra vigilant during this month.

Frequency (no. days observed/deployed) days (no. Frequency 0 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Month

Exclusion net Whales

Figure 5. Frequency (number of days observed per month) of whales (southern right whales, humpback whales, Bryde’s whales) and of exclusion net deployments (numbers of days deployed per month) in Fish Hoek over the monitoring period 1 May 2013 – 30 April 2014.

There were 23 observations (33%) of whales being present while the exclusion net was deployed, and on all but one occasion, the whales stayed >200 m away from the net. On a single occasion a whale was observed 100 -200 m from the net. On one occasion the net was not deployed at all due to the presence of whales (1 September 2013), on another occasion it was delayed by 35 min (22 September 2013) and on 11 occasions the Shark Spotters team initiated pro-active intervention as stipulated in the permit (Annexure A). This intervention involved launching the boat and then slowly riding up and down the length of the net while revving the motors, to deter the whales from approaching it. To date, the whales have responded in a satisfactory manner to the interventions, by changing direction and moving away from the net. The whales move relatively slowly which gives the operations team time to respond as required.

Dolphins There were 60 observations of dolphins in Fish Hoek over the observation period (Fig. 6). The dolphins could not be identified to species level on most occasions, but the likely possibilities are dusky dolphins (Lagenorhynchus obscurus), bottlenose dolphins (Tursiops truncates) and common dolphins (Delphinus capensis). On 2 (3%) occasions, dolphins were observed within the exclusion zone when the net was not deployed, indicating that they rarely come close to shore. The presence of dolphins peaked in March to May and November to December, with a high overlap in dolphin occurrence and exclusion net deployment (Fig. 6).

Frequency (no. days observed/deployed) days (no. Frequency 0 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Month

Exclusion net Dolphins

Figure 6. Frequency (number of days observed per month) of dolphins (common dolphins, dusky dolphins, bottlenose dolphins) and of exclusion net deployments (numbers of days deployed per month) in Fish Hoek over the monitoring period 1 May 2013 – 30 April 2014.

Dolphins were present on 21 occasions (35% of the time) when the exclusion net was deployed. On all of these occasions the pods of dolphin were small (<8 animals) and on at least 3 occasions the dolphins were engaged in hunting and feeding behaviour i.e. chasing and herding fish. Deployment was delayed on one occasion due to the presence of dolphins. On the 29 October 2013, 6 dolphins (believed to be dusky dolphins) entered Fish Hoek from the Clovelly side while the exclusion net was deployed. This was the first account of dolphins coming into the bay while the exclusion net was deployed.

The operations team, upon instruction and according to the permit, attempted to herd the dolphins out of the bay, but they were observed to be feeding on fish (juvenile yellowtail) and the herding attempt was not successful. It was subsequently determined that with these small pods herding would be unlikely be successful, especially if engaged in feeding behaviour (Michael Meyer, personal communication). The permit was thus amended and it was decided herding would only be attempted for larger pods.

On 9 occasions the boat was launched and remained on standby next to the net while the dolphins were present, and on 2 occasions the team stayed on standby on land following the revised permit. On 2 occasions a single dolphin approached the net to within 0-50 m. The dolphins swim faster than the whales, and therefore there is less time to respond. Coupled with the high overlap of occurrence and deployments, entanglement risk is higher than for other animals recorded.

Seals Seals were regularly observed in Fish Hoek, but due to their frequent occurrence it was not feasible to record their presence near the exclusion net on a consistent and quantified basis. Therefore, only noteworthy events were recorded. On two separate occasions a seal was observed chasing baitfish into the exclusion net, on another two occasions seals were observed jumping over the net. Seals were regularly observed swimming alongside the net while it was being deployed, retrieved and operational. Seals pose a low entanglement risk.

3.2.4. Seabirds

Although a variety of seabird species are regular visitors to Fish Hoek, like with the seals, it was not possible to quantify their presence and only noteworthy events were recorded.

Penguins A single observation of a penguin was recorded within 50 m of the exclusion net; it was observed swimming past the net.

Cormorants On 26 January 2014 a juvenile Cape cormorant (Phalacrocorax capensis) became entangled and drowned in the exclusion net. To date, this is the only entanglement recorded throughout the trial. The incident was observed by one of the Shark Spotters divers who saw the bird diving after shrimp that were aggregating next to the net near the pivot buoy. According to the snorkeler the bird was hit on the head by one of the leaded ropes which had been picked up by a swell. The diver tried to rescue the bird, but its head got caught in one of the holes and it drowned before it could be brought to the surface. The bird was kept and handed to a DEA official as per the permit requirements. The incident was unfortunate, but unlikely to happen regularly.

Other On two occasions crabs were released from the net as it was retrieved and on one occasion an octopus was pulled up and released. Jellyfish of various species were sometimes caught in the net; where possible the jellyfish were removed and returned to the water.

3.3. Effects on physical environment

In a joint project with the Council for Scientific and Industrial Research (CSIR), a fixed camera was installed overlooking Fish Hoek bay to monitor water circulation and sediment dynamics. The camera was installed in November 2013 and has been collecting still images (10 per hour). These images will be used to model the circulation patterns and sediment dynamics to determine whether erosion or deposition has taken place as a result of the presence of the exclusion net. However, due to the high variability and highly dynamic nature of circulation and sediment dynamics in the bay, coupled with seasonal changes, it is not possible at this stage to assess the impact of the exclusion net on the physical environment. It has been determined that a minimum of one year is necessary, but most likely two years to be able to assess this criterion (Dr. Christo Rautenbach, CSIR, personal communication). The monitoring should thus be continued in the future. However, in the short-term no obvious impacts were noted e.g. no sand accumulation next to the exclusion net while it was deployed and the mooring block remained buried. It is a reasonable assumption that the exclusion net is unlikely to have long-term, negative impact on the physical environment because it is not permanently in place i.e. it’s removed daily and not deployed all year.

3.4. Final evaluation

The impact of the net on the natural environment, including marine life, has proven to be minimal. Overall, the exclusion net has been successful in achieving a low environmental impact, with a single entanglement and mortality (Cape cormorant) throughout all 130 deployments, despite the high frequency of various marine animals in Fish Hoek.

The following key points must be noted:

a) White sharks, bronze whalers, hammerheads and rays were successfully excluded from the area enclosed by the exclusion net. No entanglements of sharks or rays occurred. This provides support that the design is an appropriate shark safety measure for Fish Hoek. b) Fish of various species were not adversely affected by the presence of the exclusion net and no entanglements of fish occurred. c) Whale presence peaked outside the main deployment period and whales responded well to interventions. No entanglements occurred and entanglement risk is considered to be low. d) Dolphin presence peaked during the main deployment presence and dolphins did not respond to intervention. No entanglements were recorded, but entanglement risk is considered to be medium. e) Seals were regular visitors in the bay, but no entanglements occurred and their entanglement risk is considered to be low. f) Seabirds were regular visitors in the bay, and a single entanglement of a Cape cormorant occurred. The entanglement risk for seabirds is considered to be low. g) Impact on the physical environment cannot be quantified (yet) and as per the CSIR’s recommendation, a longer monitoring period is required. However, due to the dynamic and highly variable nature of sediment movement, the light-weight and ‘porous’ structure of the net and the relatively short durations that the net is in place, it is unlikely that the net will have a significant impact on the physical environment. No obvious changes to the physical environment were noted.

3.5. Impact on treknet activities

During the process of designing the net, concerns were raised by the treknet fishermen operating at Fish Hoek beach about the potential impact of the net on their fishing activities. In order to address this concern, to promote involvement of the fishermen in the process, and to offset any potential losses to the fishing crews, the treknet fishermen were contracted by the Shark Spotters to perform the role of the beach crew during the deployment and retrieval process.

During the early part of the trial, the treknet management and crew determined that they would prefer to end their role in the process. This was unfortunate; however, the exclusion net team respected the decision of the treknet management and crew and sourced an alternative beach crew.

3.6. Actual records of any interactions or conflicts

The exclusion net was deployed more frequently than the number of occasions that treknet fishing took place; both peaked over the spring and summer months when white shark and fish activity are highest (Fig. 1 & 7). In total, there were 35 occasions (27%) when treknet activities occurred when the exclusion net was deployed. On two of these occasions, the deployment of the net was delayed due to trek net activities.

5 Frequency (no. days observed/deployed) days (no. Frequency

0 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Month

Exclusion net Fish Treknet

Figure 7. Frequency of exclusion net and trek net deployments (number of days deployed per month) and frequency of fish (bait fish, game fish, unknown) observed (number of days observed per month).

There was no statistical difference in catch success, whether the exclusion net was in our out (a two-tailed Fischer’s Exact test; p = 0.3058) (Fig. 8). Out of the 35 records, the fishermen were successful at catching the fish 25 times (72%), they were unsuccessful 5 times (14%), and it was not recorded 5 times (14%). Out of the 5 times that they were not successful at catching the fish while the exclusion net was deployed, there was only a single record showing that the fish (mullet) had behaved unusually by swimming towards the net, and then quickly swimming away from it (3 January 2013).

10 No. of catches of No.

0 Fish not caught Fish caught Not recorded Exclusion net - not deployed 0 10 5 Exclusion net - deployed 5 25 5 Catch success

Exclusion net - not deployed Exclusion net - deployed

Figure 8. Catch success of treknetting in Fish Hoek when the exclusion net was and was not deployed (n = 50)

The results summarised in section 3.2.2 show that the target species rarely use the exclusion zone and tended to stay in deeper waters, and that in general, the fish were not adversely affected by the presence of the net. It is therefore unlikely that the exclusion net was the reason why the fish were not caught by the treknet fishermen.

There was a record of conflict which took place on the 29 October 2013. It was the first day that dolphins had entered the bay when the exclusion net was deployed and as per the permit, the Shark Spotters crew attempted to herd the dolphins out of the bay. This caused conflict with the treknet fishermen because they believed the herding attempt scared the fish away. The conflict was resolved by both parties agreeing that: a) Daily communication between the exclusion net duty manager and the trek crew would take place with regards to fish activity b) The deployment of the net would be delayed if yellowtail were present in the bay c) Herding of dolphins would not be attempted for small schools (<10) as agreed by DEA and reflected in the revised permit conditions. Although the monitoring results show that fish are unlikely to be adversely affected by the exclusion net, there remains a perception by the fishermen that it does. This led to a second record of conflict about the position of the beach anchor point. The trek net fishermen were under the impression that the anchor point would always be in front of the Law Enforcement office, while the City and Spotters team had used that as an initial guideline and often the anchor point was positioned in front of the Shark Spotters hut. This conflict was resolved by both parties agreeing that:

a) Daily communication between the exclusion net duty manager and the trek crew would take place with regards to fish activity and whether the anchor point could be positioned in front of the Shark Spotters hut or the Law Enforcement hut. If yellowtail were likely to be present on a specific day, the fishermen would request that the net be anchored in front of the Law Enforcement office and not the Shark Spotters hut.

3.7. Comparison to previous years’ catch statistics

As a final metric to assess the impact of the exclusion net on the catch success of the treknet fishery, the annual catch records (DAFF, 2014) were assessed to determine whether there were any differences in catch rates for the main target species between 2013 and previous years (Table 2.). The records show that for the two main target species, the overall catch for Harders was lower compared to previous years, while the catch for Yellowtail was similar or in some cases, higher. The lower catch rates for Harders are reflected across most of the other treknet sites within False Bay (Dr. Stephen Lamberth, DAFF, personal communication) and thus it’s unlikely to be as a result of the deployment of the exclusion net, but rather driven by other environmental factors.

Table 2. Catch records (in kilograms) of fish caught by the Fish Hoek treknet permit holder (DAFF, 2014).

shark

teenbras tumpnose Year Harders Yellowtail Elf White S Sardine White S Maasbanker Kabeljou Joseph St. Skipjack Bamboo Mixed

2003 15574 2781 0 0 150 0 150 0 0 60 0 0 2004 14947 25991 0 6 0 0 200 0 9 204 0 0 2005 10358 26420 0 0 0 0 13 0 0 120 700 100 2006 7944 104685 31 60 0 1 100 5 0 0 3390 0 2007 13396 46278 0 0 0 0 0 0 103 0 10 0 2008 3904 9733 8 1793 0 1 203 0 0 0 138 0 2009 6731 26183 0 0 0 0 0 0 0 0 0 0 2010 4639 61729 0 421 0 0 3 0 0 0 0 0 2011 11885 17908 0 0 0 0 37 0 0 0 0 95 2012 7344 19029 0 0 576 0 0 0 0 0 0 0 2013 1524 17006 0 0 0 0 0 0 0 0 0 0 2014 1126 10867 0 0 0 0 0 127 0 0 0 0 *2014 only includes months January and February

3.8. Final evaluation

In general, there is minimal evidence for adverse impact on fish behaviour and treknet catch success due to the presence of the net. The following key points must be noted: a) No adverse impact on general fish behaviour due to the presence of the net was recorded. The majority of the time (83%) the fishermen caught their target fish while the exclusion net was deployed and there was no statistical difference in catch success whether the net was deployed or not. b) Conflicts arose from perceived issues, but were resolved with increased communication. These perceptions need to be managed into the future by ensuring regular communication with the fishermen. c) Annual treknet catch records are highly variable and show a decrease for Harder catches in 2013. Yellowtail catches were similar or even higher for 2013. However, due to annual catches being so highly variable and similar trends reflected elsewhere in False Bay, it’s unlikely that the lower catches for Harders are indicative of an exclusion net impact.

4. Social impact

4.1. Questionnaire results

A short structured questionnaire of 19 questions was administered to 71 members of the public during March and April 2014 by students from the University of Cape Town, School of Economics, in partnership with the Knowledge Co-op programme (Annexure D.) The aim of the survey was to probe attitudes towards the trial shark exclusion net project. The main findings are summarised below and in Fig. 9.

1. Almost half of the respondents registered high levels of perceived risk of a shark attack in False Bay 2. The majority of the respondents (59%) were satisfied with the manner in which sharks were being managed on Fish Hoek beach 3. The majority (69%) of respondents were in favour of the shark exclusion net becoming a permanent feature 4. The majority (87%) of respondents indicated a preference for a minimum impact or hands-off approach to shark management, and only 10% of respondents indicated that they were in favour of lethal control

Figure 9. Basic description of attitudes to sharks and the exclusion net trial in False Bay (n = 71) (Conradie et al. 2014).

4.2. Counts and behaviour of people using the net via camera images and observations

During exclusion net deployments, the number of water users (swimmers) inside and outside the exclusion net, were counted every hour on the hour (e.g. 8 am to 5 pm). Thousands of water users (swimmers) were observed using the exclusion net over the trial. On some days up to 150 swimmers were recorded within a single hour of observation. Swimmers inside the exclusion net behaved differently than those outside, by typically swimming much deeper compared to those outside of the area (Fig. 10).

Figure 10. Photograph of water users inside and outside the exclusion net taken from a fixed camera overlooking Fish Hoek.

The Fish Hoek Surf Life-saving Club also used the exclusion area for nipper training, and upon request, retrieval of the net was delayed to accommodate the training. Life-saving boards and craft were permitted in the area for this purpose (Fig. 11).

Figure 11. The Fish Hoek Surf Life-saving Club used the exclusion area for nipper training. Despite a white shark sighting recorded earlier on in the day on 9 Feb 2014 (date of photograph) nipper training was able to proceed.

To determine whether more swimmers used the exclusion area compared to the area not covered by the exclusion net, the counts of swimmers inside and outside at 12 pm every day were compared over the monitoring period. Significantly more swimmers were observed inside the exclusion net, compared to outside (Student’s t-test: n = 85, df = 166.568, t = 2.6423, p = 0.0045) (Fig. 12). It should however be noted that water use is considered generally higher on the southern side of Fish Hoek due to the proximity of the restaurant and amenities.

150 100 No. of water users 50 0

No. Inside ( 12 pm) No. Outside ( 12 pm) Figure 12. Number of water users (swimmers) observed a) inside and b) outside the exclusion area (n = 85).

4.3. Job Creation and Skills Development

Shark Spotters employed and trained a group of nine previously unemployed people from a local township, Ocean View, to deploy the net on a daily basis. Three existing Shark Spotters were empowered to get their 1NM skippers tickets to operate the rubber duck, and trained to manage the day to day deployment of the exclusion net. Shark Spotters also received training to improve their data collection techniques, used in the monitoring of the trial. Members of the Shark Spotters and City of Cape Town received training from the Department of Environmental Affairs (DEA), South African Whale Disentanglement Network (SAWDN) and Dolphin Action and Protection Group (DAPG) on how to respond to potential entanglements should they arise, and also developed protocols on what to do should any marine animal approach the exclusion area. The aim of this training was to equip the deployment team with the skills to proactively reduce the risk of entanglement as well as react should an entanglement occur.

4.4. Final evaluation

Overall, there was strong support for the programme amongst the public. The need to restore public confidence in Fish Hoek beach was one of the primary motivating factors behind this project, and it is therefore a notable success that the public responded well to the exclusion net.

The following key points must be noted: a) The social survey showed strong public support for the exclusion net with the majority of respondents in favour of the net becoming a permanent safety feature in Fish Hoek. b) Significantly more swimmers used the inside of the exclusion net compared to the area not protected by the exclusion net. c) Significant job creation and skills development took place as part of the trial.

5. Education and awareness

The trial received considerable attention from the media and the general public. The City of Cape Town and Shark Spotters aimed to engage and educate all interested and affected parties to ensure a good understanding of the project, and to manage expectations. This included providing general information on the trial project, shark safety methods, and the design and operation of the exclusion net compared to gill net methods. It also involved keeping the public up to date daily with regards to deployments via social media platforms.

5.1. General information, education and awareness

During the trial period the City of Cape Town issued a series of press releases (Table 3.) regarding the progress of the trial, successes, and limitations. Shark Spotters also published a number of blog posts with additional information in response to public interest, including a post explaining the difference between shark barriers and traditional shark nets. These posts had up to 2 100 views each on the Shark Spotters website (Table 4.). The information was also shared on our social media platforms: Facebook (6064 followers) and Twitter (16 950 followers).

Table 3. Press releases issued by City of Cape Town Date Title Web address 29 February 2012 City to consider a proposed trial https://www.capetown.gov.za/en/MediaReleases/Pa installation of a shark exclusion net ges/CitytoconsidtrialinstallofasharkexclnetFishHk.asp for Fish Hoek Beach x 20 February 2013 City welcomes approval of permit for https://www.capetown.gov.za/en/MediaReleases/Pa trial deployment of shark exclusion ges/Citywelcomesapprovalofpermitfortrialdeploymen nets tofsharkexclusionnets.aspx 22 March 2013 City’s commences its exclusion net https://www.capetown.gov.za/en/MediaReleases/Pa trial at Fish Hoek beach ges/CitycommencesexclusiotrialFishHoekbeac.aspx 4 October 2013 Fish Hoek shark exclusion net now https://www.capetown.gov.za/en/MediaReleases/Pa fully operational ges/FishHoeksharkexclusionnetnowfullyoperational.a spx 13 May 2014 City’s Fish Hoek shark exclusion net https://www.capetown.gov.za/en/MediaReleases/Pa trial ends successfully ges/CitysFishHoeksharkexclusionnettrialendssuccessf ully.aspx

Table 4. Blog posts about the exclusion net trial published by Shark Spotters Date Title No. of views Web address 1 March 2012 Shark nets vs. Exclusion nets 2,192 http://sharkspotters.org.za/shark- nets-vs-exculsion-nets 22 August 2013 The Fish Hoek Trial Exclusion Net 1,977 http://sharkspotters.org.za/the-fish- Project Update hoek-trial-exclusion-net-project- update 9 May 2014 The Fish Hoek shark exclusion 1,466 http://sharkspotters.org.za/the-fish- (barrier) net trial comes to an end hoek-shark-exclusion-barrier-net-trial- comes-to-an-end

The trial was also the focus of much media attention, with articles featured in the Cape Times, Cape Argus, Sunday Times, Weekend Argus, Die Burger, Rapport, and Dive Site Magazine, as well as numerous online articles and blog posts. The exclusion net team was also interviewed and filmed for a number of productions by various media houses including BBC News, Al Jazeera, Earthwatch (eNCA), Smile FM, Jacaranda FM and Cape Talk. This media exposure made it possible to educate a wide audience. The Shark Spotters team also regularly engaged with the public and addressed misconceptions on various social media platforms on the Sharks Spotters page, as well as in group pages, such as “Fish Hoek Beach” (www.facebook.com/FishHoekBeach).

5.2. Daily communication

Daily communication with the public was needed to inform people when the net was deployed and ready for use, and if it wasn’t deployed, why. This was achieved through social media. To communicate with the public on the beach a yellow flag was raised below the normal Shark Spotting flag to inform people that the net was fully deployed (Fig. 10). Once the team began to retrieve the net the flag was lowered, signalling that the net no longer formed a complete barrier. Portable signage was also put on the beach on deployment days, informing the public of the trial and the rules regarding use of the net (Fig. 13).

Figure 13. A yellow flag and signage on the beach informed water users that the exclusion net was operational and ready for use.

Flyers were produced and distributed on the beach when the net was in the water, containing all the important information about the trial, and contact details should people have any more queries (Fig. 14).

Figure 14. Educational flyer designed for the exclusion net

6. Costs

6.1. Financial Overview

The City of Cape Town Environmental Resource Management Department provided funding of R679 000 (excl. VAT) to Shark Spotters for the implementation of the exclusion net trial. The contract was formalised by amending the existing Memorandum of Agreement (MOA) between the two parties. The City of Cape Town Fleet Department also provided a 4.5m rubber duck to Shark Spotters for the duration of the trial. The total cost of the trial was R693 906, with a deficit in funding supplied of R7 859 which was covered by the Shark Spotters program.

Capital goods accounted for 44% (R308 057) of expenses during the trial, with operating costs, including labour for the deployment team, making up the remaining 56% (R385 849). A crew of nine previously disadvantaged individuals were employed during the trial to deploy and retrieve the net on a daily basis, accounting for R167 504 in labour costs. Three members of the existing Shark Spotters team received training and their 1NM skipper’s tickets and managed the daily operations of the net. Their costs, as well as those of the project and research managers, were included in the administration and management expenses. Research costs included the purchase of two GoPro cameras, an acoustic receiver and contributed to a fixed camera associated with the monitoring of the trial.

6.2. Budget Breakdown

Income R686 047 City of Cape Town R679 000 Interest received R7 047

Capital Expenditure R308 057 Net R86 301 Moorings R58 212 Trailer R25 430 Vehicle R95 000 Storage containers R38 800 Radios R4 314

Running costs R385 849 Labour R167 504 Admin & Management R110 701 Maintenance, Alterations, & Repairs R40 132 Fuel R10 637 Research R34 194 Training R19 945 Signage & Education R2 736

Surplus / (Deficit) (R7 859)

7. Conclusion

7.1. Final assessment in terms of specified permit criteria

Detailed assessment criteria were supplied by DEA/DAFF as part of the permit. See Annexure A for full details of these criteria. a) Impact on treknetting (beach-seine) catch success

During the trial period there were 35 occasions that schools of fish were present in the area and the exclusion net was in the water. On 25 occasions (83%), the treknet fishermen were successful in catching the target fish, on 5 occasions they were unsuccessful, and on 5 occasions the success of the trek was not recorded by the shark spotter on duty. There was no statistical difference in catch success whether the net was deployed or not.

Observations of fish behaviour in the presence of the exclusion net indicated that in the vast majority of cases fish behaved normally in the presence of the net, and were not scared away or otherwise negatively impacted by the net. Additionally, monitoring data showed that fish only rarely used the exclusion zone when the net was not deployed. It is also important to note that not every trek attempt would be successful, even without the presence of the exclusion net.

The permit states that the impact on treknetting should not be greater than 25%. While it is impossible to categorically state that the presence of the exclusion net had no impact on treknetting success, the weight of evidence indicates that it is unlikely that the net had a significant role to play in determining treknet success. b) Bycatch mortality

The permit states that bycatch mortality should not exceed 1% of the total allowable beach-seine catch of protected or prohibited species or 5% of the allowable beach-seine catch of permitted exploitable species. Additionally, bycatch mortalities should occur in no more than 10% of deployments.

During the trial period no bycatch of either protected or permitted exploitable species occurred, despite several fish species being observed interacting with the net.

c) Entanglement mortality

The permit states that entanglement mortalities of marine animals other than fish or sharks should not occur on more than 5% of the days the net is deployed.

Only one entanglement mortality was recorded during the entire trial period. On the 26th of January 2014 a juvenile Cape cormorant became entangled in the net and drowned. As the net was deployed on 130 days and only one mortality took place, it can be determined that entanglement mortalities took place on less than 1% (0.76%) of the days the net was deployed.

d) Public confidence in the safety of the net

The social survey confirmed that members of the public view the risk of shark attacks at Fish Hoek beach as high. The survey also confirmed that the exclusion net has significant public support, with 65% of those surveyed endorsing the exclusion net as their preferred method of shark control at Fish Hoek beach, and 69% indicating that they want the exclusion net to become a permanent feature of the beach.

Thousands of swimmers, including life-savers, used the exclusion area over the trial. Swimmers swam much deeper when they were inside the exclusion area. Furthermore, when the exclusion net was deployed, significantly more swimmers used the inside exclusion area, compared to the area not protected by the exclusion net.

e) Physical environment

The permit required that there be no significant changes in water circulation or sediment dynamics in the Fish Hoek area that can be attributed to the exclusion net.

The impact on the physical environment cannot be quantified yet, due to the relatively short duration of the monitoring period. However, no obvious changes to the physical environment were noted. As predicted, the mooring block of the sea anchor point has remained buried. f) Shark Incidents

There have been no shark incidents resulting in either injury or fatality to beach users during the trial period. As discussed in section 3, the net has successfully excluded a number of shark species from the exclusion zone. g) Performance of the net in various conditions

During the trial period, the net was tested in a variety of different weather and sea conditions. The early parts of the trial took place in autumn and winter, and as such weather and sea conditions were less ideal. This proved to be a valuable learning experience for the exclusion net team, as it allowed the team to establish clear parameters for deployment and retrieval of the net early on in the trial.

The permit requires that should the net be deployed but not working correctly due to weather or sea conditions, that the deployment criteria be updated to address this. The exclusion net team determined during the early trial period that the net has a tendency to lift off the sea floor in large swell (>2m) conditions. The deployment criteria were therefore updated to limit deployment accordingly.

Additionally, the permit required that the deployment criteria be updated if the crew experienced marked difficulty or danger in removing the net when the weather or sea state worsened. It is important to note that at no point during the trial period was marked difficulty or danger experienced in retrieving the net to the point that this would have been considered a danger to the crew or to the public. Some difficulty was experienced in the early part of the trial, but much of this was due to unfamiliarity with the process; as the trial went on, the crew became increasingly adept at deploying and retrieving the net.

Experience indicated that deployments and retrievals are hampered by large swell (>2 m) from the S, SSW and SE and strong SSE and SE winds (±30 km/h), with the combination of the two compounding the problem. The deployment criteria were therefore updated to limit deployment to fair - moderate weather conditions. In order to ensure that the retrieval is not hampered, the exclusion net crew remain vigilant to any changes in weather or sea conditions that would require removal of the net.

Finally, the permit required that deployment and retrieval criteria be updated if conditions occur in which the net comes loose or appeared likely to come loose. At no point in the trial was the net deployed in conditions which posed a risk to the structural integrity of the net or its anchor points, and at no point in the trial was there any danger of the net coming loose or being lost.

7.2. Overall assessment of the trial

In general, the exclusion net can be regarded as a success in the following areas: a) The design of the net has proven to be suitable, and is able to withstand the weather and sea conditions it is exposed to b) Daily deployment and retrieval of the net has proven feasible, thereby significantly reducing entanglement risk and other potential environmental impacts associated with permanent installations. c) White sharks, bronze whalers, hammerheads and rays were successfully excluded from the area enclosed by the exclusion net. No entanglements of sharks or rays occurred. This provides support that the design is an appropriate shark safety measure for Fish Hoek. d) The risk of entanglement remains low, with only one mortality (Cape cormorant) taking place during the entire trial. The risk of entanglement of both sharks and whales has been assessed as being low, with only dolphins posing a medium risk. e) The impact of the net on the success of treknet fishing at Fish Hoek beach is low. There was no statistically significant difference in catch success when the net was deployed and when the net was not deployed. f) Public support for the net is high, with the majority of respondents surveyed indicating that they would like to see the exclusion net becoming a permanent feature of Fish Hoek beach.

Overall, the results of the trial indicate that the exclusion net is a cost effective, non-lethal shark safety measure, with minimal impact on marine life and has strong public support.

7.3. Recommendations

Following on from the assessment of the trial, the following is recommended:

a) The exclusion net should become a permanent feature of Fish Hoek beach, to be deployed and retrieved on a daily basis. Existing operational protocols should remain in place. b) Deployment should take place from October to May due to the high spatial overlap between white sharks and water users over that period. Particular focus should be placed on deploying during weekends, school holidays, public holidays, and peak summer holiday season. c) Ongoing monitoring of the exclusion net should continue in order to monitor potential impacts on marine life, the physical environment, and fishing activities, and in order to gather additional scientific data on the functionality and efficacy of the net.

ACKNOWLEDGEMENTS The Department of Environmental Affairs and Department of Agriculture, Forestry and Fisheries are thanked for providing the research permit (RES2012/94, RES2014/02). The SAWDN provided disentanglement training, the Council for Scientific and Industrial Research co-funded research equipment and the Fish Hoek Surf Lifesaving Club are thanked for their ongoing support. The City of Cape Town and Save Our Seas Foundation are primary sponsors of the Shark Spotters program.

REFERENCES

Kock, A.A., O'Riain, M.J., Mauff, K., Meÿer, M., Kotze, D. & Griffiths, C. (2013). Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa. PLoS ONE, 8(1): e55048. doi:10.1371/ journal.pone.0055048.

Engelbrecht, T. (2013). The impact of white shark (Carcharodon carcharias) sightings and attacks on recreational water use patterns in False Bay. Honours Thesis. University of Cape Town, Biological Sciences Department.

Proposed Fish Hoek Trial Exclusion Net

Law Enforcement offices Legend

Start of Net Section

Anchor Points

Chain sections

Exclusion net Annexure B

18° 26' 4.224" E34° 8' 30.777" S

18° 26' 3.626" E34° 8' 31.185" S

18° 26' 4.085" E34° 8' 31.717" S

100 Meters Table 1. List of all white shark (Carcharodon carcharias) sighting during the trial exclusion net monitoring period (May 2013 – April 2014).

No. Date Exclusion net No. Time Time Duration Size Siren Surf zone Exclusion net Distance from net / deployed (Y/N) Sightings arrive depart (S,M,L) (Y/N) (Y/N) zone (In/Out) exclusion zone (m) 1 2013/10/19 N 1 11:11 11:16 00:05 M N N Out >200 2 2013/10/25 N 1 9:35 9:40 00:05 L Y Y In Inside 3 2013/10/29 Y 2 16:05 16:07 00:02 M Y N Out >200 4 2013/10/29 Y 2 16:33 16:39 00:06 M Y N Out >200 5 2013/11/13 N 4 12:14 12:15 00:01 M N N In Inside 6 2013/11/13 N 4 12:51 12:52 00:01 M N N In Inside 7 2013/11/13 N 4 13:42 13:44 00:02 M N N In Inside 8 2013/11/13 N 4 14:00 14:15 00:15 M N Y In Inside 9 2013/11/14 N 1 11:30 11:40 00:10 L Y Y In Inside 10 2013/11/20 N 2 12:47 12:50 00:03 S Y N In Inside 11 2013/11/20 N 2 16:46 17:11 00:25 NR NR NR Out 0-50 12 2013/11/25 Y 1 9:15 9:20 00:05 L N N Out >200 13 2013/12/10 N 1 13:23 13:32 00:09 L Y N Out 0-50 14 2014/01/03 Y 2 8:35 8:40 00:05 L Y N Out >200 15 2014/01/03 Y 2 9:42 9:50 00:08 L N N Out >200 16 2014/01/21 N 4 13:23 13:27 00:04 S Y Y Out 100-200 17 2014/01/21 N 4 13:52 14:00 00:08 M Y Y Out 50-100 18 2014/01/21 N 4 14:01 14:26 00:25 S Y N Out >200 19 2014/01/21 N 4 14:45 14:55 00:10 M Y Y Out Inside 20 2014/01/23 N 2 NR NR NR NR NR NR NR NR 21 2014/01/23 N 2 NR NR NR NR NR NR NR NR 22 2014/02/07 Y 2 14:17 14:36 0:19 S Y N Out >200 23 2014/02/07 Y 2 15:31 15:50 0:19 S Y N Out >200 24 2014/02/09 Y 1 09:50 09:58 0:08 S Y Y Out >200 25 2014/02/11 Y 4 13:22 13:30 0:08 S Y Y Out >200 26 2014/02/11 Y 4 13:41 13:46 0:05 S Y N Out >200 27 2014/02/11 Y 4 14:21 14:25 0:04 S Y N Out >200 28 2014/02/11 Y 4 15:33 15:38 0:05 S Y N Out >200 29 2014/02/12 Y 1 12:39 12:43 0:04 M Y N Out 100-200 30 2014/02/17 Y 1 14:50 15:10 0:20 M Y Y Out >200 31 2014/02/18 N 3 12:30 12:40 0:10 M Y Y In Inside 32 2014/02/18 N 3 12:30 12:39 0:09 M Y Y In Inside 33 2014/02/18 N 3 12:30 12:45 0:15 M Y Y Out 50-100 34 2014/02/19 Y 2 10:55 10:58 0:03 S Y N Out NR 35 2014/02/19 Y 2 11:33 11:40 0:07 S Y N Out NR 36 2014/03/05 N 1 09:55 10:04 0:09 L Y N Out >200 37 2014/04/22 N 1 13:31 13:33 0:02 S Y N Out >200 38 2014/04/23 N 1 14:10 14:20 0:10 L Y N Out >200 39 2014/05/02 Y 1 15:27 15:29 0:02 M Y N Out 0-50

Table 2. List of all fish sightings when exclusion net and trek net were deployed (May 2013 – April 2014).

No. Date Exclusion Treknet Fish Fish Caught Species Exclusion Closest distance Interact with net Fish behaviour net (Y/N) (Y/N) (Y/N) net zone to net (m) (Y/N) deployed (In/Out) (Y/N) 1 2013/10/25 Y Y Y Y Harders Out 0-50 Y Swam towards & alongside 2 2013/10/25 Y Y Y NR Harders Out 0-50 Y Swam towards & alongside 3 2013/11/05 Y Y Y Y Harders NR NR NR NR 4 2013/11/09 Y Y Y Y Harders Out 0-50 NR NR 5 2013/12/04 Y Y Y Y Harders Out 0-50 Y Swam towards, alongside, then away 6 2013/12/12 Y Y Y Y Yellowtail Out 0-50 Y Swam towards & away 7 2013/12/12 Y Y Y Y Yellowtail Out 50-100 N na 8 2013/12/15 Y Y Y Y Harders Out 50-100 N na 9 2013/12/20 Y Y Y Y Yellowtail Out na na na 10 2013/12/21 Y Y Y N Yellowtail Out >200 N na 11 2013/12/29 Y Y Y Y Harders Out 50-100 N na 12 2013/12/30 Y Y Y Y Harders NR NR NR NR 13 2013/12/31 Y Y Y NR Harders NR NR NR NR 14 2014/01/03 Y Y Y N Harders Out 0-50 Y Swam towards & alongside 15 2014/01/03 Y Y Y N Yellowtail Out 100-200 N na 16 2014/01/03 Y Y Y N Sardines Out >200 N na 17 2014/01/05 Y Y Y NR Harders Out 0-50 Y Swam towards, alongside, then away 18 2014/01/12 Y Y Y Y Harders Out 0-50 Y Swam towards, alongside, then away 19 2014/01/16 Y Y Y NR Harders NR NR NR NR 20 2014/01/18 Y Y Y N Yellowtail Out 50-100 N na 21 2014/01/18 Y Y Y Y Yellowtail Out >200 N na 22 2014/01/18 Y Y Y Y Yellowtail Out 100-200 N na 23 2014/01/18 Y Y Y Y Yellowtail Out 100-200 N na 24 2014/02/13 Y Y Y NR Harders NR NR NR NR 25 2014/02/16 Y Y Y Y Yellowtail Out >200 N na 26 2014/02/16 Y Y Y Y Sardines Out NR NR NR 27 2014/02/17 Y Y Y Y Yellowtail Out 50-100 N na 28 2014/02/17 Y Y Y Y Yellowtail Out 100-200 N na 29 2014/02/19 Y Y Y Y Skipjack Out >200 N na 30 2014/02/19 Y Y Y Y Skipjack Out >200 N na 31 2014/02/26 Y Y Y Y Skipjack Out >200 N na 32 2014/02/26 Y Y Y Y Skipjack Out >200 N na 33 2014/02/26 Y Y Y Y Skipjack Out 100-200 N na 34 2014/02/26 Y Y Y Y Skipjack Out >200 N na 35 2014/02/27 Y Y Y Y Skipjack Out >200 N na

Table 3. List of all whale sightings recorded while the exclusion net was deployed (May 2013 – April 2014).

No. Date Exclusion net Whales No. Sightings Species Exclusion net zone Distance from Interact with Intervention Intervention deployed (Y/N) (Y/N) (In/Out) net (m) net (Y/N) (Y/N) 1 2013/07/11 Y Y 1 Humpback Out >200 N Y Boat launched & motors revved 2 2013/08/26 Y Y 1 UKN na na na na na 3 2013/09/02 Y Y 1 UKN na na na na na 4 2013/09/06 Y Y 1 UKN Out na na na na 5 2013/09/11 Y Y Multiple UKN na na na na na 6 2013/09/22 Y Y 1 SRW Out >200 N Y Delayed deployment 7 2013/09/24 Y Y Multiple SRW Out >200 N Y Boat launched & motors revved 8 2013/09/24 Y Y Multiple UKN Out >200 N Y Boat launched & motors revved 9 2013/10/04 Y Y 2 UKN na na na na na 10 2013/10/04 Y Y 2 UKN na na na na na 11 2013/10/08 Y Y 1 UKN na na na na na 12 2013/10/09 Y Y 1 SRW Out 100-200 N Y Boat launched & motors revved 13 2013/10/11 Y Y Multiple UKN Out >200 N Y Boat launched & motors revved 14 2013/10/11 Y Y Multiple UKN Out >200 N Y Boat launched & motors revved 15 2013/10/13 Y Y Multiple UKN Out na na na na 16 2013/10/13 Y Y Multiple UKN na na na na na 17 2013/10/13 Y Y Multiple UKN Out >200 N Y Boat launched & motors revved 18 2013/10/15 Y Y 1 UKN na na na na na 19 2013/10/16 Y Y 2 SRW Out >200 N Y Boat launched & motors revved 20 2013/10/16 Y Y 2 SRW Out >200 N Y Boat launched & motors revved 21 2013/10/28 Y Y 1 SRW Out >200 N Y Boat launched & motors revved 22 2013/11/08 Y Y 1 UKN Out >200 N Y Boat launched & motors revved 23 2014/03/21 Y Y 1 UKN NR NR N N na

Results of a socio-economic impact study of the implementation of the shark exclusion net at Fish Hoek

Students: James Husband and Alexandra Pardoe, School of Economics, University of Cape Town.

Primary supervisor: Beatrice Conradie, School of Economics, University of Cape Town.

Citation: Conradie, B., Husband, J. & Pardoe, A. (2014). Results of a socio-economic impact study of the implementation of the shark exclusion net at Fish Hoek. BSc. mini thesis. School of Economics, University of Cape Town.

Methods

A short structured questionnaire of 19 questions was administered to 71 members of the public during March and April 2014. Members of the public were approached at random on the beachfront at times outside of major holidays (in order to target locals) at a time when the exclusion net was deployed (in order to achieve a good balance of individuals in favour of and against the use of the exclusion net; if we were to survey when the net was not deployed, it would potentially bias results against those who avoid the beach when the net is not in place thus possibly muting the expression of a demand for the net. The data was captured in excel and analysed in Stata. The main purpose of the survey was to probe attitudes towards the pilot shark exclusion programme that has been in operation in Fish Hoek Bay since March 2013.

Results

The main results of the survey are summarised in Figure 1. More than two thirds of respondents indicated that they were in favour of the shark exclusion programme becoming permanent. This position is consistent with 87% of responses indicating a preference for a minimum impact or hands- off approach to shark management. In fact the majority of those indicated to be in favour of a hands-off approach (65% of the total) in the middle panel of Figure 1, specifically selected an exclusion net as the preferred control method. In contrast only 10% of respondents indicated that they were in favour of lethal control.

Figure 1: Basic description of attitudes to sharks in False Bay (n=71)

The high demand for the exclusion net is consistent with the relatively high levels of perceived risk of a shark attack in False Bay. Almost half of the members of the public we spoke to registered high levels (>7/10) of perceived risk of a shark attack. A further 35% of observations indicated that there is some non-trivial concern about shark attacks, while less than one in five respondents felt minimal concern about the possibility of a shark attack in False Bay.

Table 1: Correlates of feelings towards a permanent shark net exclusion programme at Fish Hoek beach (n=71)

Against the In favour Characteristic net of the net ANOVA n=22 n=49

Perceived risk of an attack (1= no risk, 10= big risk) 3.00 8.04 198.78*** % swimmers 59% 33% 4.55** % of households with children (<16 years) 45% 55% 0.55 Age of respondent 50 43 2.65† % males 51% 41% 2.04† % preferring hands-off approach to shark management 36% 16% 3.57*

***p<0.01, ** p<0.05, * p<0.10, †p<0.20

Table 1. probes a little deeper regarding who is opposed to the net. We know that the opposers are a small minority, but by understanding more about who they are, one can better formulate a response to try and address their concerns. Firstly, perceived risk of a shark attack on its own explains 87% of the variation in the variable measuring a preference for or against the exclusion net becoming a permanent feature1. In Table 1. the average risk index for those against the net is 3/10, while those in favour of the net becoming permanent registered a fear factor of 8/10; clearly those who want the net gone clearly do not think that sharks represent a material problem at Fish Hoek beach, or elsewhere in False Bay. Swimmers are more highly represented amongst opposers of the net than amongst supporters.

We expected the presence of young children in a household, the respondent’s level of education and his or her level of information to play a role in shaping attitudes to the net, but neither of these factors vary systematically with attitudes to the net. Age and gender are the only factors which explain some of the attitudes; those against the net tend to be older than those in favour of it and males tend to be over represented amongst opposers compared to those in favour of the net.

This preliminary survey does not really shed much light on how these attitudes are shaped. We expect that where and how people obtain their information about the shark problem, e.g. whether they attend local talks where they might be influenced by other disgruntled locals or read the local newspapers which might favour a particular one-side view of the problem, might influence their attitudes to the net. It might also make a difference whether people feel that they are sufficiently informed or not in order to make their own assessment of the matter, but neither of these variables varied systematically with attitudes to the net either. Furthermore, local residents don’t feel any different from outsiders. People’s fears of the risk posed by net to other marine life did not vary with

1 Logit model regression preference for a permanent net (1=yes, 0=no) on the perceived risk index value their attitudes to the net, and neither was there a systematic feeling about the plight of the treknet fishers.

To conclude then, we would say that whether a person wants the net to become permanent or not is intensely personal matter, about which the individual does not necessarily think very objectively.

Fish Hoek Shark Exclusion Net Survey

Determine the socio-economic impact of the implementation of the shark exclusion net at Fish Hoek beach

Your data will be treated confidentially

You are free to decline to participate in the survey or to leave out any of the questions.

This research has been approved by the Commerce Faculty Ethics in Research Committee.

The survey will take approximately 5 minutes.

IMPACT OF THE SHARK EXCLUSION NET ON YOUR CHOICE OF BEACH

1) On a scale of 1 to 10 rate the risk of shark attack on the beaches on False Bay

1 2 3 4 5 6 7 8 9 10 unsure No real risk Very real risk

2) Are you happy with the way the risk of shark attack is managed in Cape Town? a. Yes b. No c. Unsure

3) Do you think there is enough information available about the exclusion net and how it works? a) Yes b) No c) Unsure

4) What is your MAIN source of information about the net? [TICK ONLY ONE] a) Internet b) TV programmes c) Newspapers d) Sign boards e) Pamphlets f) Public talks g) Friends or family h) Other i) None of the above

5) Is the possiblility of animal entanglement a concern of yours? a. Yes b. No c. Unsure

6) Would you still support the shark exclusion net if it resulted in reduced catches or income for the treknet fishers on the beach? [SKIP THIS QUESTION IF YOU DO NOT CURRENTLY SUPPORT THE EXCLUSION NET] a. Yes b. No c. Unsure

7) Which group/s are responsible for sharks and their management in Cape Town? [TICK ALL THAT APPLY] a. Department Environmental Affairs b. Department Agriculture, Forestry and Fisheries c. City of Cape Town d. Researchers e. Shark Spotters f. SANParks g. Navy h. NSRI i. Life-savers j. Cape Nature k. NGO’s. Name______l. Other (specify)

8) Which of the following do you consider to be acceptable forms of management to reduce shark attacks in Cape Town [TICK ALL THAT APPLY] a. Culling to reduce population b. Kill shark responsible for attack c. Exclusion nets d. Shark Spotters e. Do nothing (hands off approach) f. Other (specify) g. Unsure

9) Do you think the exclusion net is big enough? a. Yes b. No c. Unsure

10) Do you think the times of deployment are sufficient in keeping beach users safer? a. Yes b. No c. Unsure

11) Do you think the exclusion nets should become a permanent feature of Fish Hoek beach? a. Yes b. No c. Maybe

PROFILE OF THE RESPONDENT

1. What province and town/suburb do you live in?

2. Age

3. Gender a. Male b. Female

4. Where did you swim today? a. I did not swim today b. I swam inside the exclusion net c. I swam outside the exclusion net d. I swam both inside and outside the net e. Unsure

5. Highest level of education a. Incomplete high school b. Matric (Grade 12) c. FET college d. University e. Other

6. Occupation a. Still in fulltime education b. Unemployed c. Retired d. Home maker e. Craftsman/tradesman f. Independent businessmen g. Professional h. Retail i. Artist/ author j. Other

7. Do you know the difference between the Fish Hoek exclusion net and the shark nets off KwaZulu Natal a. Yes b. No c. Unsure

8. How many other people are with you on the beach today?

a. Adults (>16 years of age)

b. Children (≤ 16 years) ______